Glad that u have no trouble after trimming the roms, but GW group suggested that we should not do that.
Funny.....do you do everything you are told to?
Trimmed ROMS work quite fine if you know what you are doing. The reason Gateway says (if they even do) DON'T USE TRIMMED ROMS....is because it presents one more potential problem for people successfully using their product.
If you only trim type 1 roms of the zeros and don't change their partition layout (by removing update data) then everything I have tried has worked. I have trimmed and mounted/launched more than 40 games including the CARD1 eShop dumps. Now could some of them crash at some point.....possibly but I have heavily played 4 of those games so far and had no issues. What would be really usefull is if we could get http://3ds.essh.co/ to add a column for trimmed and people could report working or not.
Ultimately trimming is a personal choice (lol) but no harm in trying and I have had a very successful Gateway experience since launch never having bricks, lockups, save corruption or anything. Trimming can save considerable space and with trimming I have managed to get 35 games on a 32GB exfat card. We just need a site that essentially reports the ROMS that fail mount/launch or crash when trimmed. I would be more than happy to report to a site like that as there are similar wikis for ps2/psp/wii/gc isos.